JPH0446081Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an oscillating cylinder capable of linear motion and rotation at any time.

[Background technology]

For example, with the advancement of automation through robotization of automatic work machines and machine tools, and the emergence of even more highly accurate and multifunctional machine tools, pneumatic cylinders are no longer limited to simply reciprocating and direct movement. , rocking cylinders to which rotational motion is applied have come to be provided.

However, in such conventional swing cylinders, the piston and rod move and swing as one body, so the piston is strongly pressed against the rod cover or head cover at the front and rear ends of the linear motion, so it is difficult to swing the cylinder. In this case, the frictional resistance between the piston and the rod cover or head cover is large. In addition, since the rod integrated into the piston that slides inside the cylinder moves and rotates directly using the bush of the rod cover and the sliding surface between the cylinder and the piston as a bearing, there is a frictional resistance between the piston and the cylinder when the rod swings. becomes larger,
There was a problem that it was difficult to move when swinging, especially when starting.

Therefore, as a swing cylinder that solves this problem, for example, a swing cylinder described in Japanese Patent Publication No. 1983-33457 is known.

This swinging cylinder has a structure in which the piston and the rod are connected to each other via a thrust bearing and a needle bearing, and the rod can freely rotate around the axis of the rod relative to the piston. The piston is not entrained, thus eliminating the problems mentioned above.

However, in this type of swing cylinder, it is not possible to apply thrust to the pulling side of the rod, and if the axes of the rod and piston are relatively tilted due to variations in parts machining or assembly, However, this problem has not been solved with the swing cylinder described in Japanese Patent Publication No. 46-33457 mentioned above.

On the other hand, a cylinder described in Japanese Utility Model Application Publication No. 118304/1983 is known as a cylinder that solves these problems.

This cylinder includes a rotating body having a protruding piston rod and a convex spherical surface on its outer peripheral surface, and a bearing provided on the piston and having a receiving surface for the rotating body formed of a concave spherical surface. The rotating body is supported by the bearing, and the rod is rotatable about the axis of the rod with respect to the piston, and the axes of the rod and the piston are supported by the spherical center of the spherical part. It is said that the structure is relatively tiltable.

However, in a cylinder bearing having such a structure, a concave spherical surface is formed on almost the entire inner peripheral surface of a block-shaped divided member, and the divided members on which this concave spherical surface is formed are connected to each other to form an integral body. Because of the structure, it is necessary to process multi-area spherical parts on the dividing member and rotating body during production.
Easier machining of parts and reduction in manufacturing costs are hindered, and both the bearing and the rotating body are increased in size, hindering weight reduction.

Furthermore, since the spherical parts of the dividing member and the rotating body have many areas, errors in the accuracy of the spherical parts are likely to occur, and this accuracy error hinders the smooth operation of the piston rod, and also causes the spherical parts to wear out. This easily prevents the cylinder from extending its life.

In addition, since the contact surfaces of the dividing member and the spherical part of the rotating body are multi-area, abrasion powder of sealing material, bearing material, etc. generated by repeated operations becomes a paste together with lubricant, and The lubricant seeps into the contact surface and remains there, and as the lubricant is not replenished, the lubricity of the contact surface is further deteriorated.As this progresses, heat is generated between the dividing member and the rotating body, and paste-like wear powder is formed. The lubricant gradually gels, impeding smooth operation, and wears out the spherical surface, impeding the longevity of the cylinder.

[Purpose of invention]

An object of the present invention is to provide a swing cylinder that can operate smoothly, be easily manufactured, reduce manufacturing costs, be smaller, be lighter, and have a longer life.

[Summary of the idea]

The structure of the swing cylinder of the present invention includes a piston that reciprocates within a cylinder tube, and a rod that protrudes from one end surface of the piston and is capable of linear movement along the axial direction and swinging movement around the axis. a rotating body on which the rod protrudes and has a convex spherical surface on its outer peripheral surface; and a bearing provided on the piston and having a receiving surface for the rotating body formed of a concave spherical surface. The rotating body is supported by the bearing, and the rod is rotatable about the axis of the rod with respect to the piston, and the axes of the rod and the piston are supported by the spherical center of the spherical part. A rocking cylinder which is relatively tiltable, wherein the bearing is constituted by a pair of rings disposed opposite to each other at a predetermined interval via the rotating body, each of which The structure is such that the concave spherical surface portions are respectively formed on the inner peripheral portion of the ring on the opposing surface side.

〔Example〕

FIGS. 1, 2, and 3 are a front sectional view, a plan view, and a side sectional view, respectively, showing an embodiment of the swing cylinder according to the present invention.

In this embodiment, 1 is a block-shaped cylinder body, and one end of this body 1 has a head cover 2.
A cylinder tube 3 which is closed by a cylinder tube 3 and a cylinder tube 6 whose both ends are closed by head covers 4 and 5 shown in FIG. 2 are attached. A piston 8 to which a magnet 7 is attached is provided in the cylinder tube 3 so as to be slidable in the axial direction.
A bolt 12 is screwed into the end face of the piston 8 to fix the magnet 7 via a retainer 9 and a washer 11. Bumper 10 is sandwiched between retainer 9 and washer 11. The head cover 2 around the bolt 12 is provided with a recess 13 that sufficiently accommodates the head of the bolt 12 and through which compressed air is supplied and discharged from the port 24b.
In addition, 14 is a piston packing provided on the outer periphery of the piston 8, and 15 is a wear ring.

On the other hand, a recess 16 is provided on the right end surface of the piston 8, and a cup-shaped fitting 17 is screwed into this recess 16. A stud 18 as a rotary body having a rotor 18a, and a pair of rings 19 as bearings whose receiving surfaces for the stud 18 are formed by a smooth concave spherical surface part 19a and slidably support the stud 18 are arranged. It is set up.

The stud 18 as a rotating body has a substantially cylindrical shape, and both end corners of this substantially cylindrical shape are cut into convex spherical surfaces to form convex spherical portions 18a, respectively.

On the other hand, the pair of rings 19 as bearings
As shown in the figure, the rings 19 are disposed facing each other at a predetermined interval on the left and right sides of the figure through studs 18, and the inner peripheral portions of the opposing surfaces of each ring 19 are cut to form concave spherical portions 19a, respectively. It is formed. Further, the pair of rings 19 are arranged on the left side (FIG. 1) inner wall surface of the recess 16 of the piston 8 and the right side (FIG. 1) inner wall surface of the fitting 17 on both left and right (FIG. 1) end surfaces in the axial direction. Sliding contact with stud 18
It is configured to be slidable in a direction perpendicular to the axial direction of the shaft.

20 is a piston rod, and a stud 18 is screwed into the end of the piston rod 20 so that the piston rod 20 projects from the stud 18.

Numeral 21 is a nut that prevents the rod from falling off.

22 is a bumper attached to the end face of the fixture 17. Reference numeral 23 denotes an air chamber provided in the cylinder tube 3 between the piston 8 and the main body 1, and air pressure is supplied and discharged through a port 24a and a through hole 25 provided in the main body 1.

Two bearings 26, 2 are located approximately at the lower center of the main body 1.
Case 28 and rod bush 29 through 7
so that it can rotate freely and not be displaced in the axial direction.
The rods 20 are provided at regular intervals.
is supported slidably in the axial direction. A pinion 30 is attached to the rod 20 in the gap so that it rotates integrally with the rod 20 and is movable in the axial direction. 31 is a rod packing that seals the gap between the case 28 and the rod 20, and 32 is a fixture for the rod packing 31.
28a is a gasket that seals the gap between the main body 1 and the case 28.

The rod 20 must have a shape that transmits the rocking motion from the pinion 30 and that the rod packing 31 that prevents air pressure from leaking from the air chamber 23 is sufficiently effective, so a square cross section is used in this embodiment.

The lid 33 includes a wave washer 26a for adjusting machining errors in the main body 1, and two bearings 26, 27.
is screwed in to secure it.

34 is a rack meshed with the pinion 30, and the rack 34 is positioned relative to the pinion 30 and in the circumferential direction within the cylinder tube 6 by a rack guide 34a and a positioning pin 34b, and is capable of movement only in the axial direction. . At both ends of this rack 34, there are pistons 35 that slide within the cylinder tube 6, as shown in FIG.
36 is attached. These pistons 3
Air chambers 37 and 38 are provided between the head covers 4 and 5 and the head covers 4 and 5 to receive and discharge air pressure. Air pressure is supplied and discharged from the air chamber 37 through the gap between the outer surface of the cylinder tube 6 and the inner surface of the head covers 4 and 5 through the two ports 24c shown in FIG.
It is connected to 38. As shown in FIG. 3, each piston 35, 36 has a rod packing 39 on its outer periphery.
40 and wear rings 41 and 42 are attached. Numerals 43 and 44 are adjustment screws that adjust the amount of movement of each piston 35 and 36. Note that 7a and 7b shown in FIG. 1 are position sensors that detect the position of the magnet 7. In addition, 45, 46 shown in FIG.
are magnets provided integrally with the pistons 35 and 36, and position sensors 45a and 45a are mounted on the head covers 4 and 5 to detect the positions of the magnets 45 and 46, respectively.
46a is provided.

Next, the operation of the swing cylinder having such a configuration will be explained.

In this swing cylinder, the linear position of the rod 20 is obtained by detecting the sliding amount of the piston 8 in the cylinder tube 3, and the rotational position of the rod 20 is obtained by detecting the sliding amount of the pistons 35, 36 in the cylinder tube 6. Obtained by detecting. First, air pressure is supplied to either the recess 13 or the air chamber 23 in the cylinder tube 3, and when the other air pressure is released, the piston 8 moves into the cylinder 3.
The piston rod 20 slides inside the case 2.
8 and the rod bush 29, it slides and is displaced in the forward or reverse direction in the axial direction.

On the other hand, the air chambers 37, 3 in the cylinder tube 6
When air pressure is supplied to one of the pistons 8 and the other air pressure is released, the pistons 35 and 36 are displaced in the forward or backward direction while sliding within the cylinder tube 6. This displacement action also moves the rack 34 in the same direction, rotating the pinion 30 meshing with the rack 34. As the pinion 30 rotates, the piston rod 20 also rotates. As a result, the rod 20 can perform rotational and linear motions separately or linearly while rotating. Therefore, if this swing cylinder is used in an automatic working machine such as a robot, complex work can be performed.

By the way, as mentioned above, the rod 20 moves linearly and rotates, but this rotation is caused by the stud 18 moving in the ring 1.
It is not transmitted to the piston 8 by rotating inside the piston 9. Therefore, the piston 8 moves only in the axial direction within the cylinder tube 3 and does not rotate. Further, the rod 20 is rotatably supported by two bearings 26 and 27, and its rotation is extremely smooth. For this reason, the torsional rotation, that is, rocking, of the rod 20 becomes easy.

Furthermore, since the stud 18 is supported by the ring 19 as a spherical bearing, the axes of the piston 8 and the rod 20 can be tilted relative to each other using the spherical centers of the spherical parts 18a and 19a as fulcrums. Even if the axes of the piston 8 and the rod 20 are manufactured with relative inclinations due to variations in processing or assembly, the inclination between them can be absorbed, so from this point of view as well, the piston 8 or the rod 20 The linear movement of the rod 20 and the swinging movement of the rod 20 can be made smoother.

In addition, the above-mentioned smoothing can prevent the sliding surfaces of the piston 8, rod 20, etc. from being worn out. Moreover, the pair of rings 19 are in sliding contact with the recess 16 of the piston 8 and the inner end surfaces of the fitting 17 at both end faces in the axial direction, and can slide in a direction perpendicular to the axial direction. Even if the ring 19 is displaced perpendicular to the axial direction for some reason, the ring 19 will also be displaced perpendicular to the axial direction in response to the displacement, and the ring 19 will also be displaced perpendicular to the axial direction of the rods 20 and studs 18. It is possible to absorb displacement in the direction.

In addition, in this embodiment, especially the stud 1
The bearings for 8 are a pair of rings 19, i.e.
As shown in FIG. 1, they are disposed facing each other at a predetermined interval on the left and right sides of the figure through studs 18, and the inner peripheral portions on the opposing surfaces are cut to form concave spherical portions 19a, respectively. By forming a concave spherical surface on almost the entire inner peripheral surface of the block-shaped divided member, the pair of divided members can be connected to each other to form an integral part. Unlike conventional bearings, the bearing and rotating body can be manufactured without machining multi-area spherical parts, making it easier to process parts and reducing manufacturing costs. Furthermore, by reducing the size and weight of the rotating body, and by reducing the size and weight of the rotating body, this type of swing cylinder can be made smaller and lighter.

Furthermore, as described above, since the spherical portions 18a, 19a of the stud 18 and ring 19 require only a small area, errors in accuracy of the spherical portions 18a, 19a are reduced. Also, when assembling, adjust the tightness of the screw of the fixture 17 to ensure that the stud 1
Since the axial clearance between the piston rod 8 and the pair of rings 19 can be easily adjusted, the piston rod 20 can operate smoothly through this improvement in accuracy, and the wear resistance of the spherical parts 18a and 19a can be improved. This makes it possible to extend the life of this type of swing cylinder.

Furthermore, the stud 18 and the ring 19
Since the spherical parts 18a and 19a of the ring 18a and 19a have a small area, the stud 18 and the pair of rings 1 can be assembled easily.
9 and the fitting 17 can be sufficiently filled with lubricant such as grease.
It is possible to constantly replenish lubricant to the contact surfaces of a, and the abrasion powder of the sealing material and bearing material generated due to repeated operation can be removed from the conventional bearing, which is constructed by connecting divided block-shaped parts to each other. Since the piston rod 20 does not become like a paste and is not present on the contact surfaces of the spherical parts, smooth operation of the piston rod 20 can be achieved from these points as well, and the wear resistance of the spherical parts 18a and 19a is improved. This makes it possible to extend the life of this type of swing cylinder.

〔effect〕

According to the present invention, the rotary body is supported by the bearing, and the rod is rotatable around the axis of the rod with respect to the piston, and the axes of the rod and the piston are connected to the ball of the spherical portion. Since the rod is relatively tiltable about the center as a fulcrum, the straight movement and rocking movement of the rod can be made smoother.

In particular, even if the axes of the piston and rod are assembled with relative inclinations due to variations in parts processing or assembly, the inclination between them is absorbed by the above-mentioned tiltable structure. , the linear movement of the piston or rod and the swinging movement of the rod can be made smoother.

Further, by smoothing the linear movement and the swinging movement described above, it is possible to prevent the sliding surfaces of the piston, rod, etc. from being worn out.

Further, the bearing for the rotating body is constituted by a pair of rings that are disposed opposite to each other at a predetermined interval via the rotating body, and the inner circumferential portion of each ring is formed with the recess on the opposing surface side. By having a structure in which spherical parts are formed respectively, a concave spherical part is formed on almost the entire inner peripheral surface of the block-shaped divided member, and the pair of divided members are connected to each other to form an integral structure. Unlike conventional bearings, the bearing and rotating body can be manufactured without machining multi-area spherical parts, making it easier to process parts and reducing manufacturing costs. This type of swing cylinder can be made smaller and lighter by making the rotating body smaller and lighter.

Furthermore, as mentioned above, since each spherical part of the rotating body and its bearing has a small area, errors in accuracy of each spherical part are reduced, and when assembling, the tightening of the screws of the fixture 17 can be adjusted. Since the axial clearance between the stud 18 and the pair of rings 19 can be easily adjusted through adjustment, this improvement in accuracy allows for smoother operation of the piston rod, and also improves the wear resistance of each spherical part. This makes it possible to extend the life of this type of swing cylinder.

Furthermore, since the spherical parts of the rotating body and its bearings require only a small area, it is possible to sufficiently fill the space between the stud 18, the pair of rings 19, and the fixture 17 with lubricant such as grease during assembly. This makes it possible to constantly replenish lubricant to the contact surfaces of the spherical parts 18a and 19a of the stud 18 and ring 19, and furthermore, the abrasion powder of the sealing material and bearing material that is generated due to repeated operation can be removed from the conventional block. Unlike bearings that are integrally constructed by joining two separate members together, it is less likely that the paste will become paste-like and interpose on the contact surface of the spherical part.
From these points as well, the operation of the piston rod can be made smoother, and the wear resistance of each spherical surface portion can be improved, making it possible to extend the life of this type of swing cylinder.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an embodiment of a swing cylinder according to the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a side sectional view thereof. 1...Main body, 3, 6...Cylinder tube, 8
... Piston, 17 ... Fixture, 18 ... Stud (rotating body), 18a ... Convex spherical surface part, 19 ... Ring (bearing), 19a ... Concave spherical surface part, 20 ... Rod, 23 ... Air Chamber, 26, 27...Bearing, 2
8...Case, 29...Rotsdobutsuyu, 30...
...Pinion, 35,36...Piston, 37,3
8...Air chamber.

Claims (1)

[Scope of utility model registration request] A piston that reciprocates within a cylinder tube, a rod that protrudes from one end surface of the piston and is capable of linear movement along an axial direction and rocking movement around the axis, and the rod is provided in a protruding manner. a rotating body having a convex spherical surface on its outer peripheral surface; and a rotary body disposed in a recess on the one end surface side of the piston so as to be slidable in a direction perpendicular to the axial direction, and a rotary body having a convex spherical surface on the outer circumferential surface thereof; A bearing whose bearing surface is formed by a concave spherical part,
The rotating body is supported by the bearing, and the rod is rotatable around the axis of the rod with respect to the piston, and the axes of the rod and the piston are relative to each other with the center of the spherical portion as a fulcrum. A rocking cylinder that can be tilted freely, wherein the bearing is constituted by a pair of rings that are arranged opposite to each other at a predetermined interval via the rotating body, and the A swing cylinder characterized in that the concave spherical surface portions are formed on the inner circumferential portion of the surface side.